91 VFR 750 wont start...

Discussion in '3rd & 4th Generation 1990-1997' started by nbogert, Jun 10, 2010.

  1. nbogert

    nbogert New Member

    Joined:
    Jun 10, 2010
    Messages:
    22
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Wyomissing PA
    Hey guys. I bought the bike from a close friend who's father passed away a year ago.It was his father's bike, and I've know him for 20 years. He had it 4 or 5 years, I have it now for a month. Not sure how many miles on it, the tach cluster has been changed. I do know that I put about 550 miles on it in 3 weeks time. Yeah, I like to ride. Here's the issue. I noticed the starter going bad. I would get the rrrrrreeeeiitt! sound while starting. So..I picked up a starter clutch at a bike junk yard. From what I and the guy know..it should be the right year, or an interchangeable one. Anyway. B4 I changed the starter clutch, the bike ran great, except for the occasional bum start needed lol. So, on Saturday I swapped the starter clutches. Everything went great, gears matched up perfectly, no slop or forcing needed. But I snapped a bolt in the crankcase and drilled it out keeping the gears and internals covered so no metal shavings get into anything. So, the bike sat till the weather broke and I could oil it up and start it today. 3 days without oil, crankcase on. In the rain with a complete cover(totally enclosed cover) on it. I put oil in today and go to start it...cranks over FANTASTIC!!! but doesnt pick up and start. I choked it...nothing...then thought it may be flooded..so I took the choke off and cranked it with the throttle wide open...nothing. I smell raw fuel near the exhaust so Im thinking the fuel pump still works. I took of the oil fill cap and cranked it, and the Clutch spins, so that tells me the starter clutch works. I didnt pull a plug yet to see if they are fouled, I just wanted to see if any1 on here knew of anything that these bikes were known for. Hoping for something easy. But...yeah..I thought the crankcase would go on easy. PLEASE help..thanks guys.

    Neil Bogert
     
  2. betarace

    betarace New Member

    Joined:
    Mar 1, 2007
    Messages:
    1,806
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Middleburg, VA
    not to be a jerk, but is the ignition toggle switch on that is over the throttle?
    perhaps you inadvertently disconnected the coil? check for spark on one of the plugs
     
  3. nbogert

    nbogert New Member

    Joined:
    Jun 10, 2010
    Messages:
    22
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Wyomissing PA
    Lol...no worries. The run/stop switch is set to run. Ignition on...enough fuel lol. Battery is great..all coils/wires to/from plugs are connected..Im about to go out an pull a plug to see if its getting spark or fouled.
     
  4. tinkerinWstuff

    tinkerinWstuff Administrator Staff Member

    Country:
    United States
    Joined:
    Oct 5, 2009
    Messages:
    7,831
    Likes Received:
    90
    Trophy Points:
    78
    Location:
    Colorado Front Range
    Map
    550 miles in 3 weeks? I did 249miles today alone. :biggrin:
     
  5. squirrelman

    squirrelman Member

    Country:
    United States
    Joined:
    Jul 27, 2006
    Messages:
    9,838
    Likes Received:
    743
    Trophy Points:
    128
    Location:
    Buffalo, NY
    Map
    After you check the fuses.......

    Time to inspect the plugs, check gap and color maybe replace them since you don't know how long they've been in.

    Possibly a contact problem inside stop/run switch ?
     
  6. nbogert

    nbogert New Member

    Joined:
    Jun 10, 2010
    Messages:
    22
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Wyomissing PA
    NICE! But for a new/old bike that I dont know, bugs and such, 550 on three weeks with a solid 10 days of rain, and working 50 hrs a week isnt that bad.

    Pulled a plug. Wet and black. Going to replace them. I hope that works.

    The on/off swich isnt the problem because it cranks. If it wasnt working, it wouldnt even crank right?
     
  7. betarace

    betarace New Member

    Joined:
    Mar 1, 2007
    Messages:
    1,806
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Middleburg, VA
    the bike will crank (but not fire) with the switch in the off position. check fuses as SQMan said. Try to ground a plug while cranking to see if it sparks
     
  8. nbogert

    nbogert New Member

    Joined:
    Jun 10, 2010
    Messages:
    22
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Wyomissing PA
    Wait what?? I only have owned 2 motorcycles. A 2004 Kawi ZX6r and now this one. I know for sure the Kawi wont crank with the run/stop set to stop. I know because thats a game a friend would play at a stop light with me. Hit the stop switch, "hahaha" yeah, knuckle head. So I would have to switch it to the on position to fire it back up. And this bike wont crank with it off either. Already tried it. Now my 2 bikes could be the only ones out there like that, but I know that to be true for them.

    And fuses check out ok.
     
  9. betarace

    betarace New Member

    Joined:
    Mar 1, 2007
    Messages:
    1,806
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Middleburg, VA
    I can tell you definitively that the Gen3 will crank and not fire with the switch off. When I change my oil (as recently as last week) I crank without firing to fill the filter and build pressure. I dont like dry starts ever.
     
  10. nbogert

    nbogert New Member

    Joined:
    Jun 10, 2010
    Messages:
    22
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Wyomissing PA
    Really? Mine wont. It doesnt make sense to me. If you are riding, and have an engine issue, u need to kill it quik..u hit the stop switch. It kills the engine. I know it kills the spark for sure, I would think it would just act as an interupter to the ignition circuit. I would also think the kill switch would be directly tied into the crank switch so it follows that part of the harness, instead of running a seperate wire. I dunno. I must have Alien technology, and be around Alien technology all the time. I know a 04 Kawi 636, 99 Honda CBR 600, early 90s VMAXX, 07 ZX10r and my bike....wont crank with the kill switch set to off. I dont mean to be rude, or sound like an ass, but I know this for sure. Does it make a big deal? Should I concern myself with switching it around?
     
  11. betarace

    betarace New Member

    Joined:
    Mar 1, 2007
    Messages:
    1,806
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Middleburg, VA
    I think we are both saying the same thing, and may be a clue about your issue. The way the switch works:

    Bike running, hit switch - ignition cuts - bike turns off
    Bike not running, hit switch and crank ignition, cranks forever due to no ignition
     
  12. karazy

    karazy New Member

    Country:
    Canada
    Joined:
    Sep 3, 2008
    Messages:
    553
    Likes Received:
    1
    Trophy Points:
    16
    Location:
    Halifax, Nova Scotia, Canada
    Map
    For starters, my gen4 doesn't crank with the kill switch off (open cct). The headlights still turn off, but that is done with a mechanical switch in the starter button. The ignition diagram makes it look like it just kills the ground of the coils. The wiring diagram shows that it actually cuts the fuel (fuel cut relay) and the ignition + starter + [fuel pump, gen4 only] fuse (D) is isolated. It looks like the problem may lie with the ones that do turn over.

    :crazy:
     
  13. nbogert

    nbogert New Member

    Joined:
    Jun 10, 2010
    Messages:
    22
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Wyomissing PA
    I have no friggin idea. ARRRHG!! lol. Ok so. I pulled the plugs, all were fouled. Changed the plugs and tested to see if they have spark. Set one on the frame while connected to the plug wire..cranked the engine on RUN and on OFF and no spark. The I thought, maybe it's that plugs coil. So I checked another plug and get the same thing. I really dont think its the RUN/STOP switch. I dont have any idea. Any1 know where to go next?
     
  14. karazy

    karazy New Member

    Country:
    Canada
    Joined:
    Sep 3, 2008
    Messages:
    553
    Likes Received:
    1
    Trophy Points:
    16
    Location:
    Halifax, Nova Scotia, Canada
    Map
    I would start by checking the pulse gen and the ICM.
     
  15. nbogert

    nbogert New Member

    Joined:
    Jun 10, 2010
    Messages:
    22
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Wyomissing PA
    Ok..ill look them up in the book. Anything I should know about either job? Like how to, lol ...I do have a voltmeter. So Im guessing just hit them with that? Any1 have any Idea on what readings I should get? Would a bad starter relay produce these symptoms? I'm sorry guys. I can use a wrench pretty well..just was never an electric buff. Thanks again for the help.
     
    Last edited: Jun 12, 2010
  16. ArkieVFR

    ArkieVFR New Member

    Country:
    United States
    Joined:
    Jul 27, 2018
    Messages:
    1
    Likes Received:
    0
    Trophy Points:
    1
    I know this thread is over 8 years old, and you haven't been on in a while, but I'm suffering from the same problem, it's driving me mad, and at this point I'm trying everything I can think of, including replying to an ancient thread to get a response from a person that hasn't been on in forever
     
Related Topics

Share This Page